Decathlon is a French sports goods supermarket - they do a lot of own brand stuff. I've got a pair of their own brand SPD pedals that are decent enough for the price (half compared to Shimano stuff).

Their UK site: http://www.decathlon.co.uk/EN/

Never actually ridden a Decathlon bike, but they do a whole range - from full carbon beauties to supermarket quality carbon steel heavyasf*ck tanks. Soo... I'd say if the brand doesn't put you off and if its a nice frame I'd go for it.

J